An Empirical Evaluation of the Inferential Capacity of Defeasible Argumentation, Non-monotonic Fuzzy Reasoning and Expert Systems

Several non-monotonic formalisms exist in the field of Artificial Intelligence for reasoning under uncertainty. Many of these are deductive and knowledge-driven, and also employ procedural and semi-declarative techniques for inferential purposes. Nonetheless, limited work exist for the comparison across distinct techniques and in particular the examination of their inferential capacity. Thus, this paper focuses on a comparison of three knowledge-driven approaches employed for non-monotonic reasoning, namely expert systems, fuzzy reasoning and defeasible argumentation. A knowledge-representation and reasoning problem has been selected: modelling and assessing mental workload. This is an ill-defined construct, and its formalisation can be seen as a reasoning activity under uncertainty. An experimental work was performed by exploiting three deductive knowledge bases produced with the aid of experts in the field. These were coded into models by employing the selected techniques and were subsequently elicited with data gathered from humans. The inferences produced by these models were in turn analysed according to common metrics of evaluation in the field of mental workload, in specific validity and sensitivity. Findings suggest that the variance of the inferences of expert systems and fuzzy reasoning models was higher, highlighting poor stability. Contrarily, that of argument-based models was lower, showing a superior stability of its inferences across knowledge bases and under different system configurations. The originality of this research lies in the quantification of the impact of defeasible argumentation. It contributes to the field of logic and non-monotonic reasoning by situating defeasible argumentation among similar approaches of non-monotonic reasoning under uncertainty through a novel empirical comparison

Taking charge of the information glut

pp. 101-11

CUSTOMER JOURNEYS ON ONLINE PURCHASE: SEARCH ENGINE, SOCIAL MEDIA, AND THIRD-PARTY ADVERTISING

As the technologies and better practices become broadly available, companies are moving more quickly from a single-click or search-only model toward greater sophisticated models of informing and influencing the customer online shopping journeys. This study scrutinizes the predictive relationship between three referral channels, search engine, social medial, and third-party advertising, and online consumer search and purchase. The results derived from vector autoregressive models suggest that the three channels have differential predictive relationship with sale measures. Such differential relationship is even more pronounced for the long-term, accumulative effects. The predictive power of the three channels is also considerably different in referring customers among competing online shopping websites. This study offers new insights for IT and marketing practitioners in respect to how different channels perform in order to optimize the media mix and overall performance

Overload of information or lack of high value information: lessons learnt from construction

Information and knowledge are strategic assets, processed to attain objectives, perform actions and make decisions. However, technological innovations can change the format of information and often result in more complicated project information or knowledge management tools whilst this can provide information to an individual more easily and quickly. Current systems have little or no regard for the value of the information they contain. As projects draw to a close, some organisations are now asking what information is worth retaining and how might it be reused. This paper addresses the problems of information overload and value in the construction industry. Exploratory studies compared two major consultants in the UK from three perspectives (business, project management and document management). Major challenges in the current information evaluation practice in the industry were identified. Information overload does exist in the industry and is getting worse because of the heavy but often inappropriate use of search and collaborative technologies. Loss of high value information due to staff leaving is a major problem, but the companies are reluctant to evaluate recorded information (before or after storage) for future retrieval. From the strategic point of view, there is a lack of information evaluation tools that quantify the benefits and costs of performing information evaluation activities and the effects on storage. Based on these findings, a through-life Information Evaluation Methodology (IEM) has been proposed to allow high value information to be easily retrievable in the future in order to support through-life knowledge and information management (KIM) practice

The Suppressor of AAC2 Lethality SAL1 Modulates Sensitivity of Heterologously Expressed Artemia ADP/ATP Carrier to Bongkrekate in Yeast

The ADP/ATP carrier protein (AAC) expressed in Artemia franciscana is refractory to bongkrekate. We generated two strains of Saccharomyces cerevisiae where AAC1 and AAC3 were inactivated and the AAC2 isoform was replaced with Artemia AAC containing a hemagglutinin tag (ArAAC-HA). In one of the strains the suppressor of ΔAAC2 lethality, SAL1, was also inactivated but a plasmid coding for yeast AAC2 was included, because the ArAACΔsal1Δ strain was lethal. In both strains ArAAC-HA was expressed and correctly localized to the mitochondria. Peptide sequencing of ArAAC expressed in Artemia and that expressed in the modified yeasts revealed identical amino acid sequences. The isolated mitochondria from both modified strains developed 85% of the membrane potential attained by mitochondria of control strains, and addition of ADP yielded bongkrekate-sensitive depolarizations implying acquired sensitivity of ArAAC-mediated adenine nucleotide exchange to this poison, independent from SAL1. However, growth of ArAAC-expressing yeasts in glycerol-containing media was arrested by bongkrekate only in the presence of SAL1. We conclude that the mitochondrial environment of yeasts relying on respiratory growth conferred sensitivity of ArAAC to bongkrekate in a SAL1-dependent manner. © 2013 Wysocka-Kapcinska et al

Stabilization and control system power sensitivity study

Stabilization and control system sensitivity to power-off failure rate studied by simulated missions using block power switchin